JP3991774B2 - Folding method and post-processing apparatus - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a half-fold process, a tri-fold process, and a Z-fold process for transfer paper on which an image is formed by an image forming apparatus such as an electrophotographic copying machine, a printer, a facsimile machine, and a multifunction machine having these functions. The present invention relates to a transfer paper folding method using a folding unit for performing the above-described process.
[0002]
[Prior art]
Conventionally, there has been a post-processing apparatus shown in FIG. 7 that performs folding processing such as half-folding, tri-folding, and Z-folding on a transfer sheet on which an image is formed by an image forming apparatus.
[0003]
FIG. 7 is a configuration diagram of a conventional post-processing apparatus. The post-processing device 60 is installed such that a discharge roller 61 that discharges the transfer paper S on which an image is formed and an inlet guide plate 621 that guides the transfer paper from the discharge roller 61 to the inlet 62 of the post-processing device 60. As a result, it is connected to an image forming apparatus (not shown).
[0004]
Immediately after entering the inlet 62, there are a sensor PS1 for detecting the leading edge and the trailing edge of the transfer sheet S and a punching means 63. A registration roller 64 for correcting the bending of the transfer sheet S is provided downstream of the punching means 63. A switching member 69 for switching the transfer path of the transfer paper S is attached to the tip of the transfer paper S so as to be swung by the solenoid SD1.
[0005]
Folding rollers 651, 652, and 653 are attached above the switching member 69, and the folding rollers 651 and 652 and the folding rollers 652 and 653 are in pressure contact with each other. Above the folding rollers 651, 652 and 653, first stop means 66 is provided. The first stopping means 66 is obtained by attaching an endless belt to two rollers, and is driven by a motor M1 attached to one of the rollers. An abutting portion 661 is attached to the endless belt so that the transfer sheet S does not go ahead of the abutting portion 661.
[0006]
Below the folding roller 653 is the second stop means 67. The second stop means 67 has an endless belt attached to two rollers of different sizes, and is driven by a motor M2 attached to a small roller. The abutting portion 671 is also attached to the endless belt of the second stop means 67. A discharge roller 68 that discharges the transfer sheet S to the outside of the post-processing device 60 is provided downstream of the second stop unit 67.
[0007]
FIG. 8 is a diagram illustrating a procedure for performing the Z-folding process using the post-processing device 60. In (a), the transfer sheet S transported from the image forming apparatus is transported toward the first stop means 66 by the switching member 69 after the bending is corrected by the registration roller 64. Although the leading edge of the transfer sheet S abuts against the abutting portion 661 and stops, the registration roller 64 continues to be conveyed, so that deflection occurs near the folding rollers 651 and 652. Further, when the rear end portion of the transfer sheet S is continuously conveyed, the transfer sheet S is wound around the nip point N4 of the folding rollers 651 and 652, and a fold line e is formed.
[0008]
As the folding rollers 651 and 652 continue to rotate in the direction of the arrow in FIG. 8A, the fold line e of the transfer paper S is brought into contact with the abutting portion 671 of the second stopping means 67 as shown in FIG. 8B. Stop by hitting. If the folding rollers 651 and 652 continue to rotate as they are and the transfer sheet S bends, it is wound around the nip point N5 of the folding rollers 652 and 653 to form a fold f, and the Z-folding process is completed.
[0009]
In FIG. 8C, the transfer sheet S with the crease f passes around the folding roller 653 and is conveyed again to the second stop unit 67. At this time, the abutting portion 671 is moved to a position where the conveyance path toward the discharge roller 68 is opened by the motor M2 in FIG. The Z-folded transfer sheet S is discharged to the outside by a discharge roller 68.
[0010]
Since the positions of the abutting portions 661 and 671 can be freely changed by an endless belt, tri-folding processing and half-folding processing other than the size of the transfer paper S and Z-folding processing are also possible.
[0011]
However, in such a post-processing device 60, depending on the size of the transfer sheet S, the distance from the abutting portions 661, 671 to the nip points N4, N5 of the folding rollers 651, 652, and 653 is increased, so that the folding position is increased. Is not stable.
[0012]
In order to solve such a problem, there are two pairs of a folding roller and a driven roller pressed against the folding roller, and a folding portion where the two folding rollers are pressed against each other has been considered. Since this fold portion can be arranged at a position close to the nip point, the folding position is accurate and stable folding processing is possible.
[0013]
In the post-processing apparatus, such folding portions are provided at two locations, a first folding portion that performs the first folding of the Z-folding and the three-folding processing, and a second folding portion that performs the second folding. . When the Z-folding process is performed, the first folding process is performed at a predetermined position of the transfer paper at the first folding unit.
[0014]
The transfer paper subjected to the descending process at the first folding part is subjected to the second folding process at the second folding part. FIG. 9 is a diagram illustrating a procedure of the Z folding process by the second folding unit. The transfer sheet S is conveyed in the direction of the arrow a from the first folding portion in a shape in which the folded portion faces the folding roller side. The transfer sheet S is stopped at a half of the original length of the transfer sheet S by a sensor or the like. As shown in FIG. 9A, the two folding rollers 91 and 92 of the second folding section and the driven rollers 93 and 94 that are in pressure contact with each other rotate in the direction of the arrow, whereby the transfer sheet S is buckled and folded. It proceeds toward the nip point n of the rollers 91 and 92.
[0015]
[Problems to be solved by the invention]
At this time, as shown in FIG. 9B, only the tip t of the folded portion S, which is folded at the first folding portion, passes through the nip point n first at the nip point n, and then the transfer paper S The bending part b is caught in the nip point n. If the folding process is continued as it is, the tip t and the crease b are folded while being largely deviated. Therefore, the phenomenon of multiple folding occurs, and the folding position is not stable.
[0016]
The present invention has been made to solve the above-described problems, and provides a folding method in which a folding position is accurate, stable folding processing is possible, and multiple folding can be prevented during Z-folding processing. Objective.
[0017]
[Means for Solving the Problems]
In order to achieve the above object, the folding processing method of the present invention includes a second folding process of Z-folding performed by a folding unit having two folding rollers pressed against each other and driven rollers pressed against the respective folding rollers. In the method, the fold portion of the transfer paper on which the first fold is formed by the first folding process is in contact with one folding roller, the nip point between the one folding roller and the driven roller, and the other Between the nip point between the folding roller and the driven roller, the transfer paper is buckled by the rotation of the folding roller and the driven roller, and the transfer paper is wound around the nip point between the folding rollers to form a second fold. a step of, after the folding by reversing the rotation of the roller, the steps of releasing the nip point of the folding rollers together the transfer paper, again, the folding front Symbol folding low switching the rotation of the roller The nip point between was configured with the steps of passing said folded portion and the second fold.
[0018]
Further , the respective centers of the driven rollers may be arranged at positions closer to the nip point between the folding rollers than the respective center positions of the folding rollers.
[0019]
In order to achieve the above object, a post-processing apparatus according to the present invention includes two folding rollers that are pressed against each other, a driven roller that press-contacts each folding roller, and a drive motor that rotates the folding roller. In the apparatus, the fold point of the transfer sheet on which the first fold is formed is in contact with one folding roller, the nip point between the one folding roller and the driven roller, the other folding roller and the driven roller, The transfer paper is buckled by the rotation of the folding roller and the driven roller between the two nip points, and the transfer paper is wound around the nip point between the folding rollers to form a second fold. by reversing the rotation of the roller to release the transfer sheet from the nip point of the folding rollers together, again, the folding folding rotating the folding nip point of the rollers between said second switching rollers Eye and the folded portion and is configured to be controlled to pass.
[0020]
Further , it is assumed that any one of the driven rollers is configured to be able to come into contact with and separate from the folding roller, or the leading edge of the transfer paper is located downstream of the two folding rollers in the transport direction of the transfer paper. Detecting means for stopping the rotation of the folding roller based on the detection result of the detecting means, or each center of the driven roller is more than the center position of the folding roller. It can also be set as the structure arrange | positioned in the position near the nip point.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a structural diagram showing a state in which the post-processing apparatus B of the present invention is connected to the image forming apparatus A.
[0022]
In the image forming apparatus A, a charging device 2, an image exposure device (image writing unit) 3, a developing device 4, a transfer device 5a, a charge eliminating device 5b, and a cleaning device 6 are arranged around the rotating image carrier 1. An image forming unit is included. The image forming unit uniformly charges the surface of the image carrier 1 by the charging device 2, and then performs exposure scanning based on image data read from the document by the laser beam of the image exposure device 3 to form a latent image. Then, the latent image is reversely developed by the developing device 4 to form a toner image on the surface of the image carrier 1.
[0023]
On the other hand, the sheet is fed from the sheet feeding cassettes 7a and 7b disposed in the middle of the image forming apparatus A, the large capacity sheet feeding trays 7c and 7d disposed in the lower stage, the manual sheet feeding tray 7e disposed on the side, and the like. The transfer sheet S is sent to the transfer position via the registration roller 7f.
[0024]
The toner image is transferred onto the transfer paper S by the transfer device 5a at the transfer position. Thereafter, the charge on the back surface of the transfer sheet S is erased by the static eliminator 5b, separated from the image carrier 1, conveyed by the conveyance unit 5d, subsequently heated and fixed by the fixing device 8, and discharged by the paper discharge roller 9a. .
[0025]
When image formation is performed on both sides of the transfer sheet S, the transfer sheet S heated and fixed by the fixing device 8 is branched from the normal sheet discharge path by the transport path switching plate 9b and switched back in the reverse transport section 9c. After reversing the front and back, it passes through the image forming section again, forms an image on the back surface of the transfer sheet S, passes through the fixing device 8, and is discharged out of the apparatus by the discharge roller 9 a.
[0026]
On the other hand, the developer remaining on the surface of the image carrier 1 after image processing is removed by the cleaning device 6 to prepare for the next image formation.
[0027]
FIG. 2 is a block diagram of the post-processing apparatus B of the present invention. The transfer paper S discharged from the paper discharge roller 9a of the image forming apparatus A shown in FIG. When no post-processing is necessary, the switch 211 guides the transport path 212 to the sub-tray 213. When post-processing is performed, the switch 211 moves to a position where the conveyance path 214 is opened, and the transfer sheet S is sent to the punching device 22 through the conveyance path 214.
[0028]
The transfer sheet S that has passed through the conveyance path 214 is sandwiched by a plurality of grippers 222 that are attached to the endless belt 221 and passes under the endless belt 221. The rear end portion of the transfer sheet S becomes free when passing through the entrance of the punching device 22 and falls onto the sheet placing table 224. Thereafter, when the leading edge of the sheet comes into contact with the leading edge stopper 223, the gripper 222 is released from gripping, and the leading edge portion of the transfer sheet S also falls on the sheet placing table 224. At this time, the width direction of the transfer sheet S is aligned by the alignment plate 225. The transfer sheet S dropped on the sheet mounting table 224 is pressed by the leading end stopper 223 and stopped by coming into contact with the trailing end stopper 226, and a file is formed at the leading end of the transfer sheet S by the punch 227 as shown in FIG. A hole h for use is drilled. When the punching process is not necessary, the sheet is transported toward the transport path 228 or the discharge roller 229 when the punching process is performed. If the folding process is not necessary after the punching process, the sheet is conveyed to the discharge roller 229 and discharged to the outside.
[0029]
When the folding process is necessary, the sheet is conveyed through the conveyance path 228 to the first folding unit 23, and when only the binding process is necessary, the sheet is conveyed through the conveyance path 251 to the binding processing device 25.
[0030]
On the downstream side of the first folding part 23, there is a second folding part 24. Since the same thing is used for the 1st folding part 23 and the 2nd folding part 24, the 1st folding part 23 is demonstrated here.
[0031]
FIG. 4 is a configuration diagram of the first folding part 23. The first folding unit 23 includes folding rollers 231 and 232. The folding roller 231 can be rotated in the transport direction and the opposite direction by a drive motor (not shown). The folding roller 232 is rotatably attached to the bracket 233 and is pressed against the folding roller 231 by a spring 234. Under the folding rollers 231, 232, driven rollers 235, 236 are attached. The driven rollers 235 and 236 are rollers having a smaller diameter than the folding rollers 231 and 232. One driven roller 236 is always in pressure contact with the folding roller 232. The other driven roller 235 is pressed against the folding roller 231 by a spring or the like (not shown), but can be brought into contact with or separated from the folding roller 231 by a solenoid (not shown). A cam or a linear motor can be used instead of the solenoid.
[0032]
The center points c3 and c4 of the driven rollers 235 and 236 are arranged so as to be further inside from the center point c1 of the folding roller 231 to the center point c2 of the folding roller 232 with respect to the transport direction a. That is, the center point c3 of the driven roller 235 is downstream in the transport direction only from the center point c1 of the folding roller 231, and the center point c4 of the driven roller 236 is upstream from the center point c2 of the folding roller 232.
[0033]
In addition to this, the first folding unit 23 has a conveyance guide sheet 237 made of an elastic body that guides the transfer sheet S between the folding roller 231 and the driven roller 235. In addition, a sensor 238 as a leading end position detection unit of the transfer sheet S is provided on the left side of the folding roller 232. A light projector and a light receiver can be used as the sensor 238, but a mechanical actuator such as a protrusion may be used.
[0034]
FIG. 5 is a diagram illustrating a procedure of folding processing by the first folding unit 23. In (a), the driven roller 235 is retracted to a position away from the folding roller 231 by a solenoid (not shown), and the folding roller 231 is rotated counterclockwise by a motor (not shown). The transfer sheet S is conveyed in the direction indicated by the arrow from the right end of FIG. 5A, and passes through the gap between the folding roller 231 and the driven roller 235 by the conveyance guide sheet 237, and the folding roller 232 and the driven roller 236 The nip point N3 is reached. Since the folding roller 232 is in pressure contact with the folding roller 231, the folding roller 232 rotates clockwise and sends the transfer sheet S downstream.
[0035]
When the leading edge of the transfer sheet S is detected by the downstream sensor 238, the transfer sheet S is stopped at a predetermined position based on the signal. Accordingly, the folding position of the transfer sheet S can be accurately positioned below the nip point N1 of the folding rollers 231 and 232.
[0036]
When the folding position comes below the nip point N1, as shown in FIG. 5B, the driven roller 235 is brought into pressure contact with the folding roller 231, and the folding roller 231 is rotated in the clockwise direction opposite to the conventional one. The transfer paper S is nipped by the folding roller 232 and the driven roller 236 on the front side, and the rear side is nipped by the folding roller 231 and the driven roller 235 and fed in a direction approaching each other. As a result, the transfer paper S buckles and bends. Since the nip point N2 between the folding roller 231 and the driven roller 235 and the nip point N3 between the folding roller 232 and the driven roller 236 are inside the center points c1 and c2 of the folding rollers 231, 232, The deflection always proceeds toward the nip point N1 of the folding rollers 231 and 232.
[0037]
When the folding roller 231 is further rotated clockwise, the deflection of the transfer sheet S is wound around the nip point N1 of the folding rollers 231 and 232, and a fold a is formed as shown in FIG.
[0038]
Returning to FIG. 2, the transfer sheet S on which the crease is formed by the procedure as described above passes through the conveyance path, and the second fold is formed by the second fold part 24 by the same procedure.
[0039]
In the case of performing the middle folding using such folding parts 23 and 24, if a fold is formed in the middle of the transfer direction of the transfer sheet S on either the first folding part 23 or the second folding part 24. It can be folded into a shape as shown in FIG.
[0040]
In order to perform Z-folding, a fold is formed in a quarter of the transport direction of the transfer sheet S by the first folding unit 23, and an intermediate position of the original length of the transfer sheet S by the second folding unit 24. A crease may be formed. At this time, in order to prevent multiple folding, the second folding unit 24 performs folding processing according to the procedure shown in FIG.
[0041]
The transfer sheet S on which the folded portion S is formed in the first folding portion 23 in one-fourth of the conveyance direction is conveyed to the second folding portion 24 from the direction of the arrow a shown in FIG. The transfer paper S is accurately stopped when it is transported to a position below the nip point of the folding rollers 231 and 232 to one half of the original length by the tip position detection means such as the sensor 238. Then, the driven roller 235 comes into pressure contact with the folding roller 231 and the folding roller 231 rotates in the direction of the arrow in FIG. Then, the transfer sheet S bends toward the folding rollers 231 and 232. The folded portion S folded back by the first folding portion 23 comes into contact with the folding roller 232, and the tip t thereof is nipped by the folding roller 232 and the driven roller 236, but is nipped by the folding roller 231 and the driven roller 235. Therefore, it passes through the nip point N1 before the buckled portion.
[0042]
If the folding roller 231 continues to rotate as it is, as shown in FIG. 6B, the buckled portion after the tip t passes through the nip point N1 and a fold line b is formed. Here, the rotation of the folding roller 231 is temporarily stopped. Then, as shown in FIG. 6C, the folding roller 231 is reversely rotated to release the tip t and the crease b from the nip point N1. Then, the tip t is aligned with the newly formed crease b. Here, when the folding roller 231 is rotated again in the direction of the arrow shown in FIG. 6A, the tip t and the crease pass through the nip point N1 at the same time.
[0043]
What was formed in this way is that shown in FIG. The fold line a is a fold line formed by the first fold part 23, and the fold line b is a fold line formed by the second fold part 24.
[0044]
Further, in order to make a tri-fold as shown in FIG. 3, a fold is formed in the first folding portion 23 in the transfer paper S conveyance direction in two thirds, and then the second folding portion 24 has the original length of 3 A crease is formed in a fraction. In FIG. 3D, the crease c is formed by the first fold part 23, and the crease d is formed by the second fold part 24.
[0045]
Returning to FIG. 2, the transfer sheet S that has been folded or the transfer sheet S that has passed through the transport path 251 without being folded is transported to the binding processing device 25. The binding processing device 25 performs the binding process using either a flat binding stapler 252 that performs a binding process on an end portion of a transfer sheet on which a plurality of sheets are stacked, or a saddle stitching stapler 253 that performs a saddle stitching process. When the flat stitching process is performed using the flat stitching stapler 252, the shape shown in FIG. Sa is a bundle of transfer sheets in which a plurality of transfer sheets S are stacked, and one end thereof is bound by a staple SP. When the saddle stitching stapler 253 performs the binding process, as shown in FIG. 3F, the staple line SP is bound on the center line in the transport direction of the transfer sheet bundle Sa. However, in the case of this saddle stitching, the above folding process is not used in principle.
[0046]
When the binding process is not performed, the sheet is discharged to the outside by the discharge roller 254, and when the saddle stitching process is performed, the sheet is conveyed to the saddle stitch folding unit 26 through the conveyance path 255. The saddle stitch folding unit 26 includes a pair of folding rollers 261, a folding knife 262, and a creasing roller 263. The saddle-stitched transfer sheet bundle Sa shown in FIG. 3F is sent between the folding roller 261 and the folding knife 262 by the conveyance path 255 and stops at a predetermined position. As the folding roller 261 rotates and the folding knife 262 moves toward the folding roller 261, the transfer sheet bundle Sa is pushed between the folding rollers 261. Thereafter, the transfer sheet bundle Sa is formed with a crease by the crease roller 263, and is discharged to the trimmer through the conveyance path 264. FIG. 3G is a perspective view showing the transfer sheet bundle Sa which is creased by the saddle stitch folding portion 26. A crease is formed at the position of the staple SP by the saddle stitch stapler 253 indicated by the dotted line in FIG.
[0047]
Note that the folding processing method of the present invention is not limited to the case of the Z-folding process, and can also be applied to a case where a plurality of transfer sheets are folded by a single folding process.
[0048]
【The invention's effect】
According to the present invention, multiple folding of transfer paper can be prevented during the second folding process of Z folding.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing a state in which a post-processing apparatus of the present invention is connected to an image forming apparatus.
FIG. 2 is a configuration diagram of a post-processing apparatus of the present invention.
FIG. 3 is a perspective view of a transfer sheet processed by a post-processing apparatus.
FIG. 4 is a configuration diagram of a first folding unit.
FIG. 5 is a diagram illustrating a procedure of folding processing by a first folding unit.
FIG. 6 is a diagram showing a procedure of a folding processing method of the present invention.
FIG. 7 is a configuration diagram of a conventional post-processing apparatus.
FIG. 8 is a diagram showing a procedure for performing a Z-folding process using a post-processing apparatus.
FIG. 9 is a diagram illustrating a procedure of Z-folding processing.
[Explanation of symbols]
23, 24 Folding parts 231, 232 Folding rollers 235, 236 Followed rollers c1, c2 Folding roller center points c3, c4 Followed roller center points b Crease N1 Nip point S Transfer paper S Folding part

Claims (6)

A second folding processing method of Z-folding performed by a folding unit having two folding rollers pressed against each other and driven rollers respectively pressed against the respective folding rollers,
In a state in which the folded portion of the transfer paper on which the first fold is formed by the first folding process is in contact with one folding roller, the nip point between the one folding roller and the driven roller, and the other folding roller and the driven roller A step of buckling the transfer paper by the rotation of the folding roller and the driven roller between the nip point and the second crease by winding the transfer paper around the nip point between the folding rollers;
Thereafter, reversing the rotation of the folding roller to release the transfer paper from the nip point between the folding rollers;
Again, switching the rotation of the folding roller to pass the nip point between the folding rollers through the second fold and the folded portion,
A folding processing method characterized by comprising: Folding processing method according to claim 1, wherein the respective centers of the driven roller is arranged at a position close to the nip point of the folding rollers together than the center position of the folding rollers. A post-processing device having two folding rollers pressed against each other, a driven roller pressed against each folding roller, and a drive motor for rotating the folding roller,
In a state where the folded portion of the transfer paper on which the first fold is formed is in contact with one folding roller, the nip point between the one folding roller and the driven roller and the nip point between the other folding roller and the driven roller In the meantime, the transfer paper is buckled by the rotation of the folding roller and the driven roller, and the transfer paper is wound around the nip point between the folding rollers to form a second crease,
Then, reverse the rotation of the folding roller to release the transfer paper from the nip point between the folding rollers,
The post-processing apparatus is controlled so that the rotation of the folding roller is switched again so that the second fold and the folded portion pass through the nip point between the folding rollers. The post-processing apparatus according to claim 3 , wherein any one of the driven rollers is configured to be able to contact and separate from the folding roller. It has a detecting means for detecting the leading edge of the transfer paper on the downstream side of the two folding rollers in the conveying direction of the transfer paper, and the rotation of the folding roller is stopped based on the detection result by the detecting means. The post-processing apparatus according to claim 3 or 4 . 6. The post-processing device according to claim 3 , wherein each center of the driven roller is arranged at a position closer to a nip point between the folding rollers than each center position of the folding rollers. .

Images